Logic
1131 riddles
Riddles that derive from deduction and logical thinking.
If you counted 20 houses going to school, and then 20 houses on the left, going home, how many houses have you counted?
If you go to the movies and you're paying, is it cheaper to take one friend to the movies twice, or two friends to the movies at the same time?
Do you say, "Nine and five is thirteen," or "Nine and five are thirteen" ?
I am four times as old as my daughter. In 20 years time I shall be twice as old as her. How old are we now?
Old Mr. Tidy was found dead in his study by Mr. Fiend. Mr. Fiend recounted his dismal discovery to the police.
"I was walking by Mr. Tidy's house when I thought I would just pop in for a visit. I noticed his study light was on and I decided to peek in from the outside to see if he was in there. There was frost on the window, so I had to wipe it away to see inside. That is when I saw his body. So I kicked in the front door to confirm my suspicions of foul play. I called the police immediately afterward."
The officer immediately arrested Mr. Fiend for the murder of Mr. Tidy. How did he know Mr. Fiend was lying?
"I was walking by Mr. Tidy's house when I thought I would just pop in for a visit. I noticed his study light was on and I decided to peek in from the outside to see if he was in there. There was frost on the window, so I had to wipe it away to see inside. That is when I saw his body. So I kicked in the front door to confirm my suspicions of foul play. I called the police immediately afterward."
The officer immediately arrested Mr. Fiend for the murder of Mr. Tidy. How did he know Mr. Fiend was lying?
A clock chimes 5 times in 4 seconds. How many times will it chime in 10 seconds?
There are 2 ducks in front of 2 other ducks. There are 2 ducks behind 2 other ducks. There are 2 ducks beside 2 other ducks. How many ducks are there?
Walking home one day, you take a short cut along the train tracks. The tracks cross a narrow bridge over a deep gorge. At the point you are 3/8 of the way across the bridge, you hear the train whistle somewhere behind you. You charge across the bridge, and jump off the track as the train is about to run you down. As it happens, if you had gone the other way, you would have reached safety just before being run over as well. If you can run ten miles per hour, how fast is the train moving?
